Use range information to omit checks in TRUNCDIV/MOD operations.

tests/language/truncdiv_test.dart

Index: tests/language/truncdiv_test.dart
===================================================================
--- tests/language/truncdiv_test.dart	(revision 0)
+++ tests/language/truncdiv_test.dart	(working copy)
@@ -0,0 +1,35 @@
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+// Dart test optimization of modulo operator on Smi.
+// VMOptions=--optimization-counter-threshold=10 --no-use-osr
+
+import "package:expect/expect.dart";
+
+
+main() {
+  for (int i = -30; i < 30; i++) {
+    Expect.equals(i % 9, foo(i, 9));
+    // Zero test is done outside the loop.
+    if (i < 0) {
+      Expect.equals(i ~/ -i, foo2(i));
+    } else if (i > 0) {
+      Expect.equals(i ~/ i, foo2(i));
+    }
+  }
+  Expect.throws(() => foo(12, 0), (e) => e is IntegerDivisionByZeroException);
+  Expect.throws(() => foo2(0), (e) => e is IntegerDivisionByZeroException);
+}
+
+foo(i, x) => i % x;
+
+foo2(i) {
+  // Make sure x has a range computed. 
+  var x = 0;
+  if (i < 0) {
+    x = -i;
+  } else {
+    x = i;
+  }
+  return i ~/ x;
+}